The present invention relates to automatic program controlled profiling lathes for turning shafts such as bearing shafts, axles and the like, in particular to apparatus for limiting and defining the movement of the tool post to effect rough and finished cutting.
Lathes of the aforementioned type are provided with a tool holder, having tools capable of performing rough and finished cylindrical turning of the workpiece, which holder is mounted in a slidable post adapted to be moved reciprocally in a vertical plane at an angle to the workpiece. The post is mounted on a cross feed adapted to be moved reciprocally in a horizontal plane to the workpiece. The movement of the slidable tool post is effected hydraulically by the use of a pilot valve, controlled by a tracing lever articulatingly connected to the post. In order to effect rough cutting of the workpiece the tracing lever moves jointly with the post into engagement with one or more stops mounted at spaced intervals from the tracing lever. To carry out the actual finished contouring of the workpiece the tracing lever moves in engagement with a duplicating template which defines actuation of the post during rotation of the workpiece.
In the known lathes of this type the post is required to make several infeed and reversed movements toward a blank workpiece in order to make the necessary cylindrical rough cuts, while the workpiece is generally held stationary and before the workpiece can be turned in the finished form. In each case the infeed movement is limited by a separate stop. Generally these separate stops are arranged on an adjustable drum, which on completion of each rough cut and after the post has been moved back into its original starting position, is itself moved by a predetermined angle so as to present the stop determining the position of the post for the next rough cut. After all of the rough cuts have been performed the drum is finally moved automatically back to its original starting position.
The limitation of the in-feed movement of the tool post thus brought about, necessitates the readjustment of the drum stops when the lathe is reset for different workpiece. If such apparatus is used in automatic program controlled lathes, it is necessary to ascertain whether the stops, associated to each stage of the program, are in their initial standby position for the commencement of each rough cut. Moreover, the person operating the machine has to place the drum in the correct position before the actual programming operation can be placed into effect
It is an object of the present invention to provide an automatic program controlled profiling lathe overcoming the disadvantages and defects of the prior art.
It is a further object of the present invention to provide a lathe of the type described with a hydraulically controlled apparatus by which the operation and setting up of the tool post for forming rough cuts is simplified.
It is another object of the present invention to provide a lathe of the type described in which the need for manual adjustment and supervision of the stops for limiting the movement of the tool post in rough cutting is eliminated and is replaced with automatically controlled adjustable means.
It is still a further object of the present invention to provide a lathe of the type described having adjustable stop means for controlling the operation of the tool post, capable of automatically effecting selected sequence different rough cuts.
The foregoing objects, other objects and numerous advantages of the present invention are set forth and will be apparent from the following disclosure of the present invention.